Hi,
Why would you want to down vote? you can only remove your own votes, so you could select a task you have voted and unvote.
This voting system is not to express wether you like a particular task or not, it's to express that you would like to see this supported, that's all, then I can see what I should prioritize when I have time to work on porting addons to PlayMaker. Else keeping track of this via a forum is impossible.
bye,
Jean